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Quinazolinone annelation of the O-protected chiral pyrolidinone 74 (derived from L-aspartic acid) forms pyrrolo[2,1-fr]quinazolin-9(1ff)-one 75; subsequent desilylation affords (S)-(-)-vasicinone 10, which is identical with the natural /-product (Scheme 16) [212,213]. Asymmetric oxidation of de-oxyvasicinone 11 (via the imine enolate) with either (R)- or (S)-Davis' ox-aziridine reagent (10-camphorsulfonyloxaziridine) [214,215] provides a convenient route to both enantiomers, thus confirming the recently revised stereochemistry of natural vasicinone (Scheme 16) [212,213]. Recently another approaches to optically active pyrrolo[2,1-fr]quinazolinones 10 have been reported by Kamal et al. (lipase-catalyzed resolution) [56], and Argade et al. (asymmetric synthesis from (S)-acetoxysuccinic anhydride) [216]. One-pot synthesis of 11, and related alkaloids has been also developed by utilizing microwave irradiation by Liu et al. [217]. Biogenetically patterned short-step synthesis of pyrroloquinazolinone alkaloids is well established by On-aka [218], and for many other synthesis, see the references cited in these papers.